Solid phase chemical reactions conducted in small scale reactor vessels are conducive to automation; at least one chemical synthesizer is commercially available. This provides a reactor block with 48-96 reaction vessels, each of which can be different. Many steps still require a manual operation or are difficult to automate. For instance, the following operations present problems or are awkward:
loading the resins; PA1 loading the reagents; PA1 installing the septum; PA1 separating blocks and installing cleavage rack; PA1 separating block, removing vials and loading drier; PA1 re-packaging samples in containers suitable for specific programs; PA1 cleaning reactor block; and finally, PA1 reactor block is bulky and heavy making it difficult to transport. PA1 solvents occasionally get under septum sheet and can potentially get into an adjacent well; PA1 Teflon u-tube seal at bottom of reactor leaks; PA1 u-tube-to-exit tube transition has areas where fluid entrapment may occur; PA1 frits, septum and block may need to be replaced after a number of runs; PA1 HDPE reactor block may get stained and contaminated when using certain chemistries, and drops inadvertently falling from robot tip can collect on the flat top of reactor septum.
These are also disadvantages in using the reactor block:
Another approach is to have a system which operates in a serial mode where a single reactor or a group of reactors is handled individually. The system would consist of modular stations which would perform specific tasks and operate independently of the transport robot. The system would be scheduled to stagger the starting point of the reactors in a manner which would make the best use of the robot time (i.e., while one group of reactors are being mixed another group of reactors are being cleaved). Since multiple operations can occur simultaneously and independently, throughput can be increased and it would be possible to run reactors with different chemistries, mixing times and recipes.
One could envision developing a chemical synthesizer which is totally automated where a scientist would sit down at a computer and develop a recipe to synthesize a compound using a large selection of reagents and resins. The software would then send the appropriate commands to the automated synthesizer. The synthesizer would incorporate a robot system which would select a clean reactor vessel, add resins, add reagents, mix, drain, . . ., cleave sample, label container, dry sample, analyze sample and packaged sample for shipment.
This system would necessitate a reaction vessel suitable for automation. Ideally, the vessel would be inert, sealed, easily transported by a robot system, permit thorough resin washing and mixing, be light weight, disposable, and low cost.